Sphygmomanometer



March 31, 1953 E. F. LARSON 2,633,121

SPHYGMOMANOMETER Filed April 24, 1951 2 SHEETSQSHEET 1 F INVENTOR.

f/mer F. Larsofi cover and scale panels removed to Patented Mar. 31, 1953 UNITED STATES PATENT OFFICE SPHYGMOMANOMETER Elmer F. Larson, Arcadia, Calif.

Application April 24, 1951, Serial No. 222,555

I 3 Claims.

, 1 This invention relates to pressure gauging instruments and is directed particularly to improvements in instruments for determining when blood pressures are normal or abnormal. 7

An object of the present invention is to provide an instrument of the character stated which will show the diastolic pressure not in terms of millimeters of mercury as do conventional instruments, but in association with an age indicator, whereby an indication will be given as to whether the patients blood pressure is proper for the indicated age, or not.

The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming a part of the specification, with the understanding, however, that the invention is not to be limited to the exact details of construction shown and described since obvious modifications will occur to a person skilled in the art.

In the drawings:

Figure 1 is a view in side elevation of an instrument constructed in accordance with the present invention and shown attached to an arm for the taking of a pressure reading.

Figure 2 is a view of the instrument in front elevation, on a scale enlarged from the scale of Figure 1. T

.Figure 3 is a view in side elevation of the instrument with portions broken away.

Figure 4 is a front view of the air tank with the show the tubes and connections.

Figure 5 is a-sectional view taken substantially on the line 5--5 of Figure 3.

Figure 6 is asectional view taken substantially on the line 66- of Figure 3. Referring now more particularly to the drawings it will be seen upon reference to Figure 1, that the instrument comprises two main parts which are anair tank l0, and the customary air .bag'or cuif l2, which inuse is wrapped around a ,to the frontwall l6 whereby when the instrument is set up for use the front wall and the elements mounted thereon can be most conveniently seen. Near the top, the front Wall l6 has therein the two openings [8 and 20.

Fixed to the front wall over the opening l8, which is the air admission opening to the tank, is an inlet socket 22, having the angled passage 24 therethrough, one end of which communicates with the opening I8 as shown in Figures 3 and 6, while the other end is directed downwardly.

Also fixed to the front wall, next to the socket 22, is an outlet socket 25, which has a similar angled passage therethrough as indicated at 26,

the upper end of which communicates with the air outlet opening 26 as shown in Figure 6, while the other end is directed downwardly.

These sockets are preferably held securely in position by a. clamping means comprising a bracket 21, having a flange 28 placed against and welded to the face of the wall I6, and the three spaced fingers 29, which are in spaced parallel relation with the wall and directed downwardly.

Each of the sockets 22-25 is located between the two fingers 29 and a clamp bar 3|] is positioned across the faces of the sockets and secured to the spacer fingers 29, by screws 3|.

Adjacent to the bottom of the front wall l6 a lower clamp bracket 32 is secured. This lower clamp bracket has a flange 33 which iswelded to the wall 16 and carries two spaced fingers 34, which are directed upwardly toward the two fingers between which the socket 25 is positioned.

Between the lower bracket fingers is positioned a bottom socket 35 through which is formed an angled air passage 36, one end of which opens upwardly toward and in alignment with the downwardly directed open end of the passage 26 through the top socket 25. The other end of the air passage 36 opens laterally as shown in Figure 4, and has fixed therein an end of a coupling nipple 31.

Disposed across the lower bracket fingers 34 and lower socket 35, is a clamp bar 38 which is secured to the fingers by screws 39, thereby firmly holding the bottom socket 35 in position.

Located between the sockets 25 and 35 is a long tube saddle 40, comprising a bar 4| of suitable material having formed lengthwise therein the channel 42.

Lying in the channel 42 is the transparent tube 43 which has its ends fixed in the aligned air passages 26 and 36 of the two sockets 25 and 35.

Fitted in the sight tube is a free moving sight element 44, which comprises a solid cylinder of a light weight material, such as a plastic or light weight wood, such as balsa, having fine channels lengthwise therein, so that air may pass slowly.

The downwardly opening end of the inlet air Passage 24, has a coupling nipple 45 therein to the 3 outer end or which is connected the tube 46, to which is connected the conventional valved bulb 41, used with many types of blood pressure instruments.

Disposed against the front wall 18 and secured thereto by screws 41 is a cover 48 which comprises the top 49 and side flanges 50.

In the top 49 of the cover is an opening, or window 5| through the longitudinal center of which is seen the sight tube 43.

Disposed at each side of the sight tube is a long panel 52, one longitudinal edge of which is secured to the saddle, and each panel projects outwardly and laterally across the adjacent side of the Window 5|.

The outwardly directed, or front, face of each panel has secured thereto by screws 53, a plate '54 bearing an age scale. The screws 53 are passed through the slots 55 in the plates, whereby necessary adjustments of the plates may be made.

One scale is layed off for pressures taken from the arm, as indicated by the notation on the cover at 56 and the other for the leg, as indicated at 51.

The age notations on each scale are in two groups,- the upper group being in red, indicated at 5B and the lower group, which is a repetition of the top group, being in green, or another color, indicated at 59.

As a guide for the person taking the blood pressure readings, there are provided the two bowed, resilient line markers 60, having the back turned, or hooked, ends 6!, as shown in Figure 5. These markers are disposed across the space between the remote longitudinal edges of the plates 52, the hooked ends being engaged across such edges, as shown.

In checking the pressure of a person each marker is adjusted to cover the numerals designating the approximate age or" the person. For example, if such person is between sixty and seventy, each marker is positioned over such figures either on the arm scale, or the leg scale according to whether the chcckis to be made on the arm or leg. 7

With the markers set for these ages on the arm scale, as shown in Figure 2, the air band is secured around the arm, as shown in Figure 1, and the band is coupled to the air outlet nipple by the tube 6!. Air is then pumped into the tank and flows through the sight tube past the sight to fill and constrict the band around the arm. By gradually increasing the air pressure in the tank to a critical point, the blood pressure in circulation will be overcome to a stage that at each pulsation the blood trying to overcome the air pressure in the cuff pumps a smaller volume of air out of cuff into sight tube, sending sight to its maximum elevation in relation to blood pressure. As the heart contracts and dilates the sight will then be caused to rise and fall and if in doing this it stays between the markers it will indicate that the diastolic pressure is approximately normal.

Such up and down movements of the sight will also enable the user of the instrument to readily count the beats, or pulse, of the patient.

I claim:

1. A blood pressure indicator comprising a receptacle for air under pressure, a transparent sight tube connected at one end to the receptacle, an inflatable cuff for wrapping about a limb of the body, an air tube connecting the other end or the tube with the end, a sc'ale'd'ispos'ed magitudinally of the sight tube and having thereon an upper longitudinally spaced series of age figures and a lower longitudinally spaced series of age figures, a marker for each series, a light weight free moving air borne sight element within the sight tube, and means for forcing air into and controlling its escape from the receptacle, said tank having an inclined front wall, means secured to said Wall and supporting said sight tube vertically in front thereof, and a plate secured at one side of the sight tube and supporting said scale on the forwardly facing side thereof.

2. A blood pressure indicator comprising a receptacle for air under pressure, a transparent sight tube connected at one end to the receptacle, an inflatable cuff for wrapping about a limb of the body, an air tube connecting the other end of the tube with the cuff, a scale disposed longitudinally of the sight tube and having thereon an upper longitudinally spaced series of age figures and a lower longitudinally spaced series of age figures, a marker for each series, a light weight free moving air borne sight element within the sight tube, and means for forcing air into and controlling its escape from the receptacle,

said sight element being in the form of a cylinder fitting snugly in the sight tube and formed to permit the slow passage of air thereby, in either direction in the tube.

3. A blood pressure indicator comprising a re ceptacle for air under pressure, a transparent sight tube connected at one end to the receptacle, an inflatable cuif for wrapping about a limb of the body, an air tube connecting the other end of the tube with the curl, a scale disposed longitudinally of the sight tube and having thereon an upper longitudinally spaced series of age figures and a lower longitudinally spaced series of age figures, a marker for each series, a light weight free moving air borne sight element within the sight tube, and means for forcing air into and controlling its escape from the receptacle, said sight tube being supported on a wall of the tank by two socket members each having an air passage therethrough and between which the sight tube is supported with each end connected to a passage of a socket, said passage of one socket being connected to said tank, the passage of the other socket being connected to the cuff, a plate positioned at each side of and extending lengthwise of the sight tube, the plates being disposed in outwardly divergent relation from the interposed tube, said scale being carried on the forwardly directed face of a plate, and said markers each comprising an arcuate strip disposed across the space between the remote longitudinal edges of the plates and adjustably connected to such edges to facilitate up and down adjustment of the markers.

ELMER. F. LARSON.

REFERENCES CITED The following references are 'of record in the file of this patent;

UNITED STATES PATENTS Number Name 7 flate 2,076,642 I -Iubbard et al. Apr. 13, 1937 2,421,114 Cameron May 27, 1947 FOREIGN PATENTS N mbe country Date 753,617 France Aug. 12, 1933 

